Preheat oven to 350° Fahrenheit. Line sheet pan with parchment paper and set aside. Alternately, line loaf pan with parchment paper or lightly grease loaf pan with compatible neutral oil.
Add ground beef, eggs, almond flour, chopped onion, coconut aminos, tomato paste, salt, garlic powder, mustard powder, and black pepper to large mixing bowl. Use silicone spatula or hands as needed to mix together all ingredients until fully combined. Be careful not to overmix.
Transfer mixture to sheet pan lined with parchment paper. Place ground beef mixture in center of sheet pan and use hands to shape mixture into rectangular loaf. Alternately, transfer mixture to loaf pan and spread out evenly.
Add tomato paste, coconut aminos, mustard powder, and salt to small mixing bowl. Whisk until ingredients are fully incorporated and tomato glaze is formed.
Using basting brush, brush tomato glaze evenly over top and sides of meatloaf. Drizzle any remaining glaze over top of meatloaf.
Place sheet pan in preheated oven. Bake 1 hour, or until internal meat thermometer inserted in center of loaf reads 155°F.
When desired temperature is reached, carefully remove sheet pan from oven. Set pan aside and let meatloaf rest 5 to 10 minutes, then use sharp knife to divided loaf into desired number of slices. Serve warm with desired sides.